616
FXUS65 KTFX 262314
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
414 PM MST SUN JAN 26 2025
AVIATION SECTION UPDATED.
KEY MESSAGES
- COLD TEMPERATURES LINGER IN CENTRAL AND SOUTHWEST MONTANA VALLEYS
WHILE THE PLAINS BEGIN TO WARM UP EARLY THIS WEEK.
- BREEZY OVER THE PLAINS THIS WEEK.
- COLDER WITH OPPORTUNITIES FOR SNOW NEXT WEEKEND.
DISCUSSION
/ISSUED 106 PM MST SUN JAN 26 2025/
- METEOROLOGICAL OVERVIEW:
UPPER LEVEL RIDGING CENTERED JUST OFF THE WEST COAST WILL LARGELY
REMAIN IN PLACE THROUGH MUCH OF THE UPCOMING WEEK THANKS TO A
PERSISTENT CUTOFF UPPER LEVEL LOW ACROSS THE SOUTHWEST CONUS. AS A
RESULT, AN ANTI-CYCLONIC NORTHWESTERLY FLOW WILL REMAIN IN PLACE
ACROSS THE NORTHERN ROCKIES THROUGH MUCH OF THE UPCOMING WEEK. THIS
WILL KEEP THE LARGE SCALE CONCERNS AT A MINIMUM THROUGH MUCH OF THE
WEEK. TEMPERATURES ACROSS THE PLAINS WILL TREND ABOVE AVERAGE
THROUGH THE WEEK, WITH PERSISTENT BREEZY WINDS. IN CENTRAL AND
SOUTHWEST MONTANA VALLEYS, COLD AIR IN PLACE WILL BE A BIT STUBBORN
TO MIX OUT, HENCE A FEW MORE COLD MORNINGS WITH OPPORTUNITIES FOR
FOG WILL BE AROUND.
BY THE END OF THE WEEK THE CUTOFF LOW OVER THE SOUTHWEST CONUS
FINALLY SHIFTS EASTWARD, ALLOWING FOR A PROGRESSION OF WEATHER
SYSTEMS ONCE AGAIN. THE AFOREMENTIONED RIDGE SHIFTS EASTWARD LATE
THURSDAY NIGHT INTO FRIDAY, PASSING EAST BY FRIDAY NIGHT AS A BROAD
UPPER LEVEL TROUGH IS QUICK TO TAKE ITS PLACE ACROSS SOMEWHERE
ACROSS THE WEST. ENSEMBLES ARE IN GOOD AGREEMENT THAT A COLDER
PERIOD WILL MOVE IN THIS WEEKEND, WITH MUCH LOWER CONFIDENCE ON THE
MAGNITUDE OF THE COLD AS WELL AS HOW MUCH SNOW COMES WITH IT.
- FORECAST CONFIDENCE & SCENARIOS:
THE GREATEST UNCERTAINTY OVER THE NEXT FEW DAYS WILL BE FOR
TEMPERATURES ACROSS CENTRAL AND SOUTHWEST MONTANA VALLEYS. WITH
LITTLE IN WAY OF WIND IN THE FORECAST, THE COLD TEMPERATURES TO LOOK
TO HANG AROUND LONGER COMPARED TO OVER THE PLAINS FURTHER NORTH.
LOOKING TOWARD THIS WEEKEND, CLUSTER GUIDANCE DEMONSTRATES WHY THERE
IS GOOD CONFIDENCE FOR COOLER TEMPERATURES, BUT LOWER CONFIDENCE FOR
THE MAGNITUDE OF COLD AS WELL AS ANY PRECIPITATION AMOUNTS. 80% OF
CLUSTER MEMBERS FAVOR TROUGHING OVER OR NEAR THE NORTHERN ROCKIES.
THE MAGNITUDE AND PLACEMENT OF THIS TROUGHING IS HIGHLY UNCERTAIN
HOWEVER, WITH ROUGHLY 60% OF MEMBERS FAVORING A DEEPER, SLOWER
TROUGH ACROSS THE PACIFIC NORTHWEST SUNDAY, 20% FAVORING A SLOWER
BUT LESS AMPLIFIED TROUGH SHUNTED FURTHER NORTH THAN ALL OTHER
MEMBERS, AND ANOTHER 20% FAVORING A FASTER VERSION OF A LESS
AMPLIFIED TROUGH PROGRESSING ACROSS THE NORTHERN ROCKIES. ALL THIS
TO SAY, CONFIDENCE WITH RESPECT TO SPECIFICS IS LOW AT THIS TIME FOR
THIS WEEKEND. -AM
AVIATION
27/00Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL ACROSS ALL TERMINALS EXCEPT FOR THE KHLN
AND KBZN TERMINALS DURING THIS TAF PERIOD. THERE IS A 20% CHANCE FOR
FOG AT THE KBZN AND KHLN TERMINALS BETWEEN NOW AND 18Z TOMORROW
MORNING. HOWEVER, DUE TO CLEAR SKIES AND SOME MOISTURE FROM SNOW
MELTING THAT CHANCE IS TOO LOW. AT BOTH OF THOSE TERMINALS FOG WILL
REDUCE VISIBILITY TO AT LEAST IFR LEVELS BETWEEN 27/08Z AND 27/18Z.
IT WILL BE BREEZY AT THE KGTF, KCTB, AND KHVR TERMINALS DURING THIS
TAF PERIOD. THE WILL BE INSTANCES OF MOUNTAIN WAVE TURBULENCE AND
LOW-LEVEL WIND SHEAR ACROSS NORTH-CENTRAL MONTANA DURING THE
MAJORITY OF THIS TAF PERIOD. -IG
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION
WEATHER AND HAZARD INFORMATION.
PRELIMINARY POINT TEMPS/POPS
GTF 18 37 19 38 / 0 0 0 0
CTB 21 37 21 38 / 0 0 0 0
HLN 4 29 10 32 / 0 0 0 0
BZN -4 27 6 34 / 0 0 0 0
WYS -22 31 -14 37 / 0 0 0 0
DLN 3 27 9 34 / 0 0 0 0
HVR 18 36 17 36 / 0 0 0 0
LWT 19 39 22 42 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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